Germany has come under heavy pressure from its EU partners to abandon its veto on a huge rescue operation by the European Central Bank to prevent the eurozone from falling apart and the world from sliding into renewed recession.

With the eurozone's main €440bn bailout fund in tatters, it has emerged that the ECB has been forced to intervene at an increased rate by buying up more and more distressed government bonds. Figures released on Monday showed it bought €9.5bn last week – or more than twice as much as a week earlier (€4bn).

The eurozone's 17 finance ministers began crisis talks in Brussels on Monday night "to stop the rot" with Italian bond yields – the country's cost of borrowing – hitting a new peak of 6.69%, threatening to crash the euro system, and political leaders from virtually all countries outside Germany lining up to demand full-scale ECB intervention. Bond yields of 7% would be seen by the markets as a trigger for the IMF to intervene as it did when Irish borrowing costs reached a similar level last year.

David Cameron, in the Commons, issued his starkest warning yet that the eurozone will collapse unless the ECB takes more powers to buy the bonds of countries such as Italy, where the crisis is deepening, not helped by the refusal of Silvio Berlusconi to step down as prime minister.

Telling the eurozone to sort itself out, Cameron said it was hard to understand "why some in Europe are so opposed to the ECB being more of a monetary activist".

The mood among non-Germans was summed up by one EU diplomat: "The Germans will have to be dragged kicking and screaming and it will probably come to a knife-edge before they agree to let the ECB play a bigger role." Markets have already lost faith that the euro rescue mechanism, the European Financial Stability Facility, due to see its firepower lifted to €1tn, can even remotely do the job. On Monday it was barely able to attract investors to a €3bn bond for Ireland, signalling that it will fail to raise funds in future.

Irish finance minister Michael Noonan publicly voiced doubts about the EFSF's future, saying the ECB must continue to play a parallel role "until the EFSF firewall has been put in place, whenever that may be" and even then "the ECB must carry out a parallel function until it is quite clear that the new firewall is doing its job".

So far the German chancellor, Angela Merkel, and her finance minister, Wolfgang Schäuble, have heeded warnings from the Bundesbank president, Jens Weidmann, that a prolonged bond-buying spree by the ECB would jeopardise its independence and stoke up inflation. Prompted by him, they killed off attempts led by the US at last week's G20 summit in Cannes to raid the Bundesbank and other central bank gold reserves to boost the IMF's firepower so it could effectively boost the EFSF.

The Bundesbank alone has reserves of €180bn, of which €130bn are in gold – prompting headlines such as "A grab for our gold". One abortive plan at Cannes was to convert some of these into extra "special drawing rights" at the IMF to boost German guarantees for the EFSF over the heads of the Bundestag.

But there is still hope in London and other European capitals that the Bundesbank and Berlin will relent under sheer market and political pressure, with the IMF clearly unable to persuade the oil- and gas-rich Russians to contribute more to the EFSF as Christine Lagarde, its managing director, discovered in Moscow on Monday. She now heads for China and Japan.

Cameron told MPs: "It is for the eurozone and the ECB to support the euro. Global action cannot be a substitute for concrete action by the eurozone.

"The G20 withheld specific IMF commitments at this stage precisely because we wanted to see more concrete action from eurozone countries to make their firewall credible and to stand behind their currency. In short, the world sent a clear message to the eurozone at this summit: Sort yourselves out and then we will help. Not the other way round.

"The rest of the world can play a supporting role but, in the end, this work has to be done by the eurozone countries themselves. No one else can do it for them."

He also urged Greece, which was on Monday night still waiting to see who would head its new national government, to make up its mind about the austerity programme or else the rest of the world cannot move on.

On Monday the 17 finance ministers failed to give any clear guidance on their plans for the EFSF, including its eventual firepower, as Klaus Regling, the fund's chief executive, said he and his team would have to go back to "market participants" to help decide. After issuing a paper about how to enhance the EFSF's firepower, Regling blamed the Greek political crisis for yesterday's difficulties in placing the €3bn bond and insisted that the problems had been exaggerated because German bonds are trading at their lowest yield for almost 50 years.

He also blamed lack of clarity about the fund's eventual firepower, disclosing merely that the new investment fund designed to attract overseas investors would now be known as a "co-investment fund" rather than a special purpose investment vehicle (SPIV).

Showing every sign of stress, Jean-Claude Juncker, eurogroup chairman, and Olli Rehn, EU economic and monetary affairs commissioner, made plain that the only decision taken was to demand a letter from the new national salvation government in Greece – and to scrap plans for another emergency session on 17 November.

The letter, Rehn indicated, would have to spell out that all members of the new government, particularly the two main parties, pledged to implement in full the stiffer austerity programme associated with the next €130bn bailout for the near-bankrupt country. Once that was received, he added, Greece would probably get the €8bn bailout instalment it needs to avoid bankruptcy next month.